Select column names and querying "LIKE" on Couchbase - sql

Question

I want to get all column names from a bucket.
I found a query:
SELECT ARRAY_DISTINCT(ARRAY_AGG(v)) AS column
FROM mybucket b UNNEST object_names(b) AS v
It's getting column names array but I need LIKE SQL command. It's like this:
SELECT column
FROM mybucket
WHERE column LIKE '%test%'
Is there a way to do this?

Answer 1

OBJECT_NAMES() only gives top level field names (not includes nested fields)
https://docs.couchbase.com/server/current/n1ql/n1ql-language-reference/objectfun.html
SELECT DISTINCT v AS column
FROM mybucket b UNNEST OBJECT_NAMES(b) AS v
WHERE v LIKE "%test%";

Answer 2

This is a tricky one, depending on what you want the resultant structure to be. And disclaimer, there might be a more succinct way to do this (but I haven't found it yet--maybe there's another way that doesn't involve OBJECT_NAMES?).
But anyway, the key to this for me was the ARRAY collection operator.
For instance, this:
SELECT ARRAY a FOR a IN ARRAY_DISTINCT(ARRAY_AGG(allFieldNames))
WHEN a LIKE '%test%' END AS filteredFieldNames
FROM mybucket b UNNEST object_names(b) AS allFieldNames
Will return results like
[
{
"filteredFieldNames": [
"testField1",
"anotherTestField"
]
}
]
If you want a different format, you can work with the ARRAY operator expression. For instance:
SELECT ARRAY { "fieldName" : a } FOR a IN
ARRAY_DISTINCT(ARRAY_AGG(allFieldNames))
WHEN a LIKE '%test%' END AS filteredFieldNames
FROM mybucket b UNNEST object_names(b) AS allFieldNames
Which would return:
[
{
"filteredFieldNames": [
{
"fieldName": "testField1"
},
{
"fieldName": "anotherTestField"
}
]
}
]